Annotate duplicate nodes in the ros2 node list

Signed-off-by: Emerson Knapp <emerson.b.knapp@gmail.com>

ros2node/ros2node/api/__init__.py

@@ -13,6 +13,8 @@
 # limitations under the License.
 
 from collections import namedtuple
+from typing import List
+from typing import Tuple
 
 from rclpy.action.graph import get_action_client_names_and_types_by_node
 from rclpy.action.graph import get_action_server_names_and_types_by_node
@@ -47,6 +49,24 @@ def parse_node_name(node_name):
     return NodeName(node_basename, namespace, full_node_name)
 
 
+def annotate_duplicate_nodes(node_names: List[NodeName]) -> Tuple[bool, List[str]]:
+    annotation_string = ' (non-unique name)'
+
+    any_duplicates = False
+    name_count = {}
+    for n in node_names:
+        count = name_count.get(n.full_name, 0) + 1
+        if count > 1:
+            any_duplicates = True
+        name_count[n.full_name] = name_count.get(n.full_name, 0) + 1
+
+    sorted_names = sorted(
+        n.full_name + (annotation_string if name_count[n.full_name] > 1 else '')
+        for n in node_names
+    )
+    return any_duplicates, sorted_names
+
+
 def get_node_names(*, node, include_hidden_nodes=False):
     node_names_and_namespaces = node.get_node_names_and_namespaces()
     return [

ros2node/ros2node/verb/list.py

@@ -14,6 +14,7 @@
 
 from ros2cli.node.strategy import add_arguments
 from ros2cli.node.strategy import NodeStrategy
+from ros2node.api import annotate_duplicate_nodes
 from ros2node.api import get_node_names
 from ros2node.verb import VerbExtension
 
@@ -37,4 +38,7 @@ def main(self, *, args):
         if args.count_nodes:
             print(len(node_names))
         elif node_names:
-            print(*sorted(n.full_name for n in node_names), sep='\n')
+            has_duplicates, sorted_names = annotate_duplicate_nodes(node_names)
+            if has_duplicates:
+                print('# WARNING: There are nodes in the graph that share a name')
+            print(*sorted_names, sep='\n')